A model for phosphocreatine resynthesis.
Nevill, Alan M., David A. Jones, David McIntyre, Gregory C. Bogdanis,
and Mary E. Nevill.
School of Human Sciences, Liverpool John Moores University, UK,
School of Sport and Exercise Sciences, University of Birmingham, UK,
Department of Physical Education and Sport Science, Loughborough
University, UK
APStracts 3:0443A, 1996.
Amodel for phosphocreatine (PCr) resynthesis is proposed based on a
simple electric circuit, where the PCr store in muscle is likened to
the stored charge on the capacitor. The solution to the second order
differential equation that describes the potential around the circuit
suggests the model for PCr resynthesis is given by PCr(t) = R-
(d1.exp(-k1.t) +/- [delta]2.exp(-k2.t)). Using non-linear least
-squares regression, this double exponential model was shown to fit
the PCr recovery data taken from two studies involving maximal
exercise accurately. In Study 1, when the muscle was electrically
stimulated while occluded, PCr concentrations rose during the
recovery phase to a level above that observed at rest. In Study 2,
following intensive dynamic exercise, PCr recovered monotonically to
resting concentrations. The second exponential term in the double
exponential model was found to make a significant additional
contribution to the quality of fit in both Study 1 (P<0.05)
and Study 2 (P<0.01).
Received 27 January 1995; accepted in final form 11 September
1996.
APS Manuscript Number A103-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 7 October 1996